WO2018154895A1

WO2018154895A1 - Linear motor control system

Info

Publication number: WO2018154895A1
Application number: PCT/JP2017/042564
Authority: WO
Inventors: 修平永田; 渉初瀬; 鈴木　尚礼; 小山　昌喜
Original assignee: 日立オートモティブシステムズ株式会社; 株式会社日立産機システム
Priority date: 2017-02-23
Filing date: 2017-11-28
Publication date: 2018-08-30
Also published as: JP6800041B2; JP2018137945A

Abstract

Provided is a linear motor control system capable of improving driving efficiency and vibration noise characteristics. The linear motor control system is provided with: a device provided with a mover 3 and an armature 2 and relatively reciprocating the mover 3 and the armature 2 in the axial direction, said mover 3 having one end connected to an elastic body 14 and having a permanent magnet 3a, said armature 2 having a winding 6 wound around a magnetic pole 4; and a control device 5 for controlling alternating voltage applied to the winding 6 on the basis of alternating current flowing through the winding 6 and detected by a current detection unit. The control device 5 has a fundamental wave extraction unit 58 and a current control unit 59 (harmonic attenuation unit) and controls the alternating voltage applied to the winding 6 on the basis of the fundamental wave component of the alternating current and harmonic attenuation voltage, said fundamental wave extraction unit 58 separating the alternating current flowing through the winding 6 and detected by the current detection unit into the fundamental wave component and a harmonic component, said current control unit 59 outputting the harmonic attenuation voltage capable of attenuating the harmonic component.

Description

Linear motor control system

The present invention relates to a linear motor control system having a linear motor, a compressor equipped with the linear motor, and a control device for controlling the equipment.

As a technique for realizing a reciprocating motion of a motor using a resonance frequency of an elastic body, a technique described in Patent Document 1 is known.
Patent Document 1 discloses a current waveform that creates an alternating current waveform of a first alternating current (comparison current) that serves as a reference for a drive current based on the operating state of a linear vibration motor for a linear vibration motor that supports a mover as a spring. The generator, the current detector for detecting the drive current supplied to the linear vibration motor, and the difference between the first alternating current (comparison current) and the second alternating current waveform (instantaneous value) that is the output of the current detector A motor drive control device including a control unit that controls so as to be small is disclosed. It is described that the control unit adjusts the drive current to be the resonance drive frequency of the linear vibration motor.

JP 2004-56994 A

However, the technique described in Patent Document 1 uses a control method that adjusts the drive current to the resonance drive frequency of the linear vibration motor. Therefore, although it is necessary to generate the minimum necessary current value as the command value from the viewpoint of high-efficiency driving, the current value in the resonance driving state is a friction caused by time-varying loads and mechanical variations. Since it depends on the variation of the load and the like, there is a possibility that the calculation becomes complicated. On the other hand, in the control method for generating the voltage waveform as the command value, the calculation process can be simplified. ) And the non-linearity of the motor characteristics, the harmonic component of the drive frequency is superimposed on the current waveform. When the harmonic component is superimposed on the current waveform, there is a risk of increasing motor loss or increasing electromagnetic noise in the motor unit.
Therefore, the present invention provides a linear motor control system that can improve drive efficiency and vibration noise characteristics.

In order to solve the above problems, a linear motor control system according to the present invention includes a field element having one end connected to an elastic body and having a permanent magnet, and an armature having a winding wound around a magnetic pole. A device for reciprocating the magnetic element and the armature in the axial direction, and a control device for controlling the alternating voltage applied to the winding based on the alternating current flowing through the winding detected by the current detection unit; A linear motor control system comprising: a fundamental wave extraction unit that separates an alternating current flowing through the winding detected by the current detection unit into a fundamental wave component and a harmonic component; and the harmonic A harmonic attenuation unit that outputs a harmonic attenuation voltage capable of attenuating the wave component, and controlling the alternating voltage applied to the winding based on the fundamental wave component of the alternating current and the harmonic attenuation voltage. Features.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the linear motor control system which can improve a drive efficiency and a vibration noise characteristic.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a longitudinal cross-sectional view in the axial direction of the compressor of Example 1 which concerns on one Example of this invention. FIG. 2 is a history diagram of gas compression force in a steady operation state of the compressor shown in FIG. 1. It is a characteristic view which shows the mover position dependence of the thrust constant of the compressor shown in FIG. It is a characteristic view which shows the mover position dependence of the detent force of the compressor shown in FIG. It is a control block diagram in electric current command control in a compressor. It is a figure which shows the relationship between an alternating current frequency in a constant current condition, and a needle | mover stroke. It is a control block diagram in the voltage command control in a compressor. It is a figure which shows the relationship between an alternating voltage frequency and a needle | mover stroke in voltage constant conditions. It is a figure which shows an example of the voltage waveform at the time of voltage command control, and a current waveform. It is a block diagram of the control apparatus shown in FIG. It is a figure which shows the modification of the block diagram of the control apparatus shown in FIG. It is a block diagram of the control apparatus of Example 2 which concerns on the other Example of this invention. It is a figure which shows the modification of the block diagram of the control apparatus shown in FIG. It is a block diagram of the control apparatus of Example 3 which concerns on the other Example of this invention. It is a block diagram of the control apparatus of Example 4 which concerns on the other Example of this invention.

In the present specification, a compressor will be described as an example of equipment constituting the linear motor control system, but it is needless to say that the apparatus is not limited to the compressor.
Embodiments of the present invention will be described below with reference to the drawings. Similar components are denoted by the same reference numerals, and redundant description is omitted.
The various components of the present invention do not necessarily have to be independent of each other. One component is composed of a plurality of members, a plurality of components are composed of one member, and one component is separated from another. And a part of a certain component and a part of another component are allowed to overlap.

FIG. 1 is a longitudinal sectional view in the axial direction of a compressor 1 according to a first embodiment of the present invention. The compressor 1 includes an armature 2 and a mover 3 having, for example, a plate-shaped permanent magnet 3a. Hereinafter, the mover 3 may be referred to as a field element.
The armature 2 includes a magnetic pole 4, a winding 6 wound around each of the magnetic poles 4, and a bridge 7.
The magnetic pole 4 is made of, for example, laminated electromagnetic steel plates, and can generate an electromagnetic force for reciprocating the permanent magnet 3a of the mover 3 by energizing an alternating current to the winding 6 which is an example of a supply unit. It is configured as follows. As an example, the compressor 1 shown in FIG. 1 has two pairs of magnetic poles 4 that are opposed to each other so as to sandwich the mover 3 with a gap on both sides of the mover 3 in the axial direction (vertical direction). The magnetic poles 4 having a pair and forming a pair of these two pairs are spaced apart at an interval defined by the bridge 7 along the axial direction (vertical direction). By applying an alternating current to the winding 6 wound around the two pairs of magnetic poles 4 by the control device 5, the permanent magnet 3 a is alternately attracted to each pair of the magnetic poles 4. Reciprocates. In the following, the case where the movable element 3 reciprocates in the vertical direction will be described as an example, but the direction of the reciprocating movement is not limited to the vertical direction. For example, the movable element 3 may be configured to reciprocate in the horizontal direction, or the movable element 3 may be configured to reciprocate in a direction having an arbitrary angle with respect to the vertical direction. A general term for the direction in which the mover 3 reciprocates is referred to as an axial direction.

The bridge 7 is formed of, for example, a magnetic material, and the bridge 7 serves as a magnetic path. Therefore, the coils 6 wound around the two sets of magnetic poles 4 spaced apart in the axial direction are connected in series by wiring. It can be configured. Further, when the bridge 7 is formed of a nonmagnetic material, the bridge 7 is configured to magnetically separate two sets of magnetic poles 4 spaced apart in the axial direction from each other. The coil 6 wound around can be connected in parallel by wiring. That is, the coils 6 wound around the two sets of magnetic poles 4 may be wired so that they can be energized in series, or may be wired in parallel. The wiring is not particularly limited, but in FIG. As an example, a configuration is shown in which a bridge 7 is formed of a non-magnetic material, and coils 6 wound around two sets of magnetic poles 4 are connected in parallel by wiring.

The mover 3 has a plate-shaped permanent magnet 3 a, one end is fixed to the piston 12, and the other end is connected to the resonance spring 14. The shape and number of the permanent magnets 3a can be appropriately designed according to the device to be applied, and are not limited to a flat plate shape. For example, the movable element 3 may have a cylindrical shape or a columnar shape, and a plurality of permanent magnets 3 a may be arranged on the outer peripheral surface of the movable element 3.
A piston 12 is connected to one end of the armature 3 in the direction of relative reciprocation between the armature 2 and the armature 3. For this reason, the piston 12 can reciprocate while sliding with the inner surface of the cylinder block 11 in the cylinder 11 a of the cylinder block 11 in accordance with the reciprocating motion of the mover 3. A region surrounded by the piston 12, the inner surface of the cylinder block 11, and the cylinder head 13 in the cylinder 11a becomes a compression chamber in which fluid is compressed and expanded.

The cylinder head 13 facing the end surface of the piston 12 is connected to the end surface of the cylinder block 11, and the gas in the cylinder 11a is repeatedly compressed and discharged as the piston 12 reciprocates. As a configuration for this purpose, the cylinder head 13 is provided with a suction hole (not shown) through which the gas flowing into the cylinder 11a passes and a discharge hole (not shown) through which the gas flowing out of the cylinder 11a passes. These suction holes and discharge holes are provided with check valves.

A resonance spring 14 is connected to the other end of the mover 3 in the direction of relative reciprocation of the armature 2 and the mover 3, and the restoring force of the resonance spring 14 is movable along with the reciprocation of the mover 3. It is configured to act on the child 3. When the mover 3 reciprocates in the vertical direction (axial direction), if the reciprocation matches the resonance frequency determined by the mass of the reciprocating object including the mover 3 and the spring constant of the resonance spring 14, the compressor The energy efficiency as 1 can be maintained high.

In the present embodiment, the armature 2 is stationary in the vertical direction (axial direction) and the mover 3 is reciprocated along the vertical direction (axial direction), but is not limited thereto. For example, the armature 2 may reciprocate along the vertical direction (axial direction), and the movable element 3 may be stationary in the vertical direction (axial direction), and the armature 2 and the movable element 3 may have different speeds. It is good also as a structure which reciprocates along a perpendicular direction (axial direction). In any case, it is preferable to connect one end of the resonance spring 14 to an object that moves along the vertical direction (axial direction).
Alternatively, the movable element 3 as a field element may be stationary, and the armature 2 may reciprocate in parallel with the cylinder block 11 in the axial direction of the movable element 3. In this case, for example, one end of the support member is connected and fixed to the side connected to the resonance spring 14 of the mover 3 as a field element, and the other end of the support member is grounded (fixed to the ground or floor) or installed. Secure on the table. Thereby, the mover (field element) 3 functions as a stator, and the armature 2 and the cylinder block 11 reciprocate in a direction parallel to the axial direction of the mover (field element) 3.

(Resonance frequency)
In the following description, the resonance of the mover 3 that is an object connected to one end of the resonance spring 14 in each of the case where the operation state of the compressor 1 is a no-load steady operation state and a loaded steady operation state. It will be described how the frequency is determined.

[In the case of no-load negative operation]
Next, a method for driving the compressor 1 will be described. As main forces acting on the mover 3, an electromagnetic excitation force Felec generated by applying an alternating current to the winding 6, a restoring force Fspring by the resonance spring 14, and a gas compression force due to a differential pressure between the gas inside and outside the cylinder 11 a Fgas is mentioned.
When the gas compression force Fgas is ignored, that is, when the compressor 1 has no load (unloaded condition), the resonance frequency determined by the mass M of the mover 3 and the spring constant Ks of the resonance spring 14 is electromagnetically excited. Resonance occurs when the frequency matches the frequency of the force Felec. At this time, it becomes possible to reciprocate the movable element 3 with an electromagnetic excitation force Felec, which is smaller than other drive frequencies, that is, with an alternating current having a small effective value. Here, the frequency of the electromagnetic excitation force Felec is equal to the frequency of the AC magnetic field supplied to the mover 3, and the frequency of the electromagnetic excitation force Felec can be manipulated by the frequency of the alternating current applied to the winding 6.

The resonance frequency ωn at no load is given by the following equation (1) when the attenuation coefficient is negligibly small. *

The steady operation state can mean a state in which the vibration amplitude and vibration frequency of the mover 3 are kept substantially constant for a predetermined time or longer, for example, for 5 seconds or longer. Further, in the case where an elastic body other than a spring is used, the spring constant Ks can be replaced with the magnitude of the restoring force when the elastic body is deformed by a unit length.

[In the case of load and steady operation]
When considering the gas compression force Fgas, the resonance frequency deviates from the value in the no-load condition due to the gas spring component Fr included in the gas compression force Fgas. The gas spring component Fr refers to a restoring force component proportional to the vibration amplitude of the mover 3 in the gas compression force Fgas. The gas spring component Fr is given by the following equation (2), where X is the amount of movement of the piston 12 in the stroke direction.

The coefficient of the right side X is the gas spring constant Kgas, which varies depending on the gas discharge pressure, suction pressure, cylinder diameter, and gas physical properties. Equation (2) can be regarded as an extraction of the first-order term relating to the stroke movement amount X of the piston 12 with respect to the gas compression force Fgas. Here, the gas compression force Fgas will be described in detail.

The gas compression force Fgas is determined by the product of the differential pressure inside and outside the cylinder 11a and the cross-sectional area of the cylinder 11a (cross-sectional area in a plane perpendicular to the vertical direction). Here, it is assumed that the outside of the cylinder 11a is the suction pressure. FIG. 2 is a history diagram of the gas compression force Fgas in the steady operation state of the compressor 1 shown in FIG. That is, it is a history of the gas compression force Fgas in a steady operation state in which the suction and discharge of gas are repeated in the cylinder 11a. In FIG. 2, the horizontal axis is the position x of the mover 3, and the top dead center direction is a positive direction. Here, the top dead center is the lowest position of the piston 12 in the cylinder 11 a during compression, that is, the position where the piston 12 is closest to the cylinder head 13. The position of “0” in the mover position x indicates a state in which the permanent magnet 3a constituting the mover 3 is located between the two sets of magnetic poles 4 that are spaced apart from each other in the axial direction (intermediate portion). The vertical axis represents the gas compression force Fgas. The history of the gas compression force Fgas can be classified into four processes of “suction process”, “compression process”, “discharge process”, and “expansion process”.

The “suction process” is a process in which gas is sucked into the cylinder 11a, and the load on the compressor 1 is small. The “compression process” is a process of compressing the gas in the cylinder 11a to the discharge pressure, and is a section where the load increases. The “discharge process” is a process of discharging the gas in the compressed cylinder 11a. The “expansion process” is a process in which the piston 12 at the top dead center moves toward the bottom dead center, and is a section in which the load decreases.

Here, the gas spring constant Kgas is considered. The gas spring constant Kgas is a value obtained by differentiating the gas compression force Fgas by the movement amount X of the piston 12 in the stroke direction (change amount of the position x of the mover 3) as shown in the following equation (3). *

Therefore, the values in the “suction process” and “discharge process” are small, and are substantially zero if there is no load pulsation due to pressure loss during the process. On the other hand, each of the “compression process” and the “expansion process” is a section in which the load increases and decreases as the piston 12 moves along the vertical direction (axial direction), and thus the gas spring constant Kgas is a relatively large value. It becomes. Thus, the gas spring constant Kgas becomes a periodic variable that varies while the piston 12 reciprocates once.

As described above, the resonance frequency ωL in the presence of the gas compression load has the influence of the gas spring constant Kgas on the resonance frequency ωn at the time of no load shown in the above formula (1) when the effect of the damping force is ignored. This can be expressed by the following formula (4).

Since the gas spring constant Kgas is a variable that changes according to the position of the piston 12, the resonance frequency ωL is also a variable that changes according to the position of the piston 12. Therefore, in order to resonate the piston 12 strictly, it is necessary to change the frequency of the electromagnetic excitation force Felec according to the position of the piston 12 (nonlinearity of the gas compression force and the electromagnetic excitation force with respect to the stroke movement amount).
Next, nonlinear characteristics of the gas compression force Fgas and the electromagnetic excitation force Felec that are external forces acting on the mover 3 with respect to the stroke movement amount X will be described.
As shown in FIG. 2, the gas compression force Fgas includes a higher-order component with respect to the stroke movement amount X (change amount of the position x of the mover 3) in addition to the gas spring component Fr described above. This is also clear from the fact that the gas compression force Fgas is not proportional to the stroke movement amount X. This means that the external force (gas compression force Fgas) acting on the mover 3 includes higher-order frequency components other than the fundamental frequency.
The electromagnetic excitation force Felec is obtained as the sum of the excitation thrust Fi and the detent force Fd that are substantially proportional to the alternating current applied to the winding 6. Here, the excitation thrust Fi is a force generated by the interaction between the magnetic field generated by applying an alternating current to the winding 6 and the permanent magnet 3 a constituting the mover 3. The detent force Fd is a force generated by attracting the permanent magnet 3 a to the magnetic pole 4 regardless of whether or not an alternating current is applied (applied) to the winding 6.

As described above, the excitation thrust Fi is substantially proportional to the alternating current applied to the winding 6, and this proportionality constant is referred to as a thrust constant. Here, the thrust constant will be described. When the stroke movement amount X of the mover 3 is large, the electromagnetic force generated by the interaction between the permanent magnet 3a and the armature 2 is weakened. Therefore, the thrust constant becomes small in the region where the stroke movement amount X of the mover 3 is large. FIG. 3 is a characteristic diagram showing the dependency of the thrust constant of the compressor 1 shown in FIG. 1 on the position of the mover, and schematically shows the relationship between the stroke movement amount X of the mover 3 and the thrust constant. In FIG. 3, the horizontal axis is the position x of the mover 3, and the vertical axis is the thrust constant. The position of “0” in the mover position x indicates a state in which the permanent magnet 3a constituting the mover 3 is located between the two sets of magnetic poles 4 that are spaced apart from each other in the axial direction (intermediate portion). Assuming that a constant excitation thrust Fi is generated, the thrust constant decreases as the mover 3 approaches the end of the armature 2 as shown in FIG. Is large, it is necessary to increase the current value of the alternating current applied to the winding 6. Therefore, in order to generate the electromagnetic excitation force Felec having a sine wave shape, the current waveform needs to be distorted from the sine wave shape. This means that higher-order components are included in the current waveform.

Next, the detent force Fd will be described. FIG. 4 is a characteristic diagram showing the mover position dependence of the detent force of the compressor 1 shown in FIG. The horizontal axis of FIG. 4 is the position x of the mover 3, and the state in which the permanent magnet 3a constituting the mover 3 is positioned between two sets of magnetic poles (intermediate part) spaced apart from each other in the axial direction. With reference position “0”, one direction along the axial direction of the mover 3 (for example, the direction in which the mover 3 goes downward in FIG. 1) is positive, and the other direction (the opposite direction: movable in FIG. 1). The case where the child 3 is directed negative is shown. In addition, the vertical axis in FIG. 4 is the detent force Fd, and the permanent magnet 3a constituting the mover 3 is based on a state in which the permanent magnet 3a is positioned between two sets of magnetic poles (intermediate part) spaced apart from each other in the axial direction. The position is “0”, and one direction along the axial direction of the mover (for example, the direction in which the mover 3 faces downward in FIG. 1) is positive, and the other direction (the opposite direction: the mover 3 in FIG. 1). This is a case where the negative direction is the upward direction.

As shown in FIG. 4, in the region on the positive side of the horizontal axis (mover position x), the permanent magnet 3a constituting the mover 3 is positioned between two sets of magnetic poles that are spaced apart from each other in the axial direction (intermediate). In this state, the detent force Fd is “0” because the permanent magnet 3a is located farthest from both the upper magnetic pole 4 and the lower magnetic pole 4. Thereafter, when the mover 3 moves downward along the axial direction, the lower end side of the permanent magnet 3a approaches the lower magnetic pole 4 to generate a positive detent force Fd. Further, when the mover 3 moves downward along the axial direction and the substantially central portion of the permanent magnet 3a reaches the position of the lower magnetic pole 4, the positive detent force Fd peaks, and then the mover 3 further moves. When the magnet moves downward along the axial direction and the permanent magnet 3a moves away from the position of the lower magnetic pole 4, the decant force Fd turns negative. Therefore, the profile of the detent force Fd with respect to the mover position x is nonlinear as shown in FIG. That is, the detent force Fd increases as the permanent magnet 3a approaches the magnetic pole 4, but begins to decrease at a certain approach distance. Therefore, the relationship between the stroke movement amount X of the mover 3 (the displacement amount of the position x of the mover 3) and the detent force Fd is as shown in FIG. From FIG. 4, the detent force Fd is a non-linear function with respect to the stroke movement amount X (the displacement amount of the position x of the mover 3), and when the piston 12 reciprocates in a sinusoidal manner, the detent force Fd has a higher-order frequency component. Is assumed to be included.

Due to the non-linear characteristics of the external force acting on the mover 3 as described above, when the compressor 1 is driven, the time variation waveform of the stroke movement amount X, the current waveform of the alternating current applied to the winding 6, or the voltage of the alternating voltage It can be seen that the waveform may include higher order frequency components of the drive frequency.

(Compressor drive control)
The drive control of the compressor 1 will be described. Generally, motor drive control methods are roughly divided into current command control for controlling the applied current to the winding to have a predetermined command waveform and voltage command control for controlling the applied voltage to the winding to have a predetermined command waveform. can do. In this embodiment, voltage command control is used as an example of the drive control method. First, each control method will be described below.

[Current command control]
In the current command control, the current value of the alternating current applied to the winding 6 is controlled. As described above, since the excitation thrust Fi is substantially proportional to the alternating current applied to the winding 6, it can be said that the current command control indirectly controls the motor thrust. FIG. 5 shows a control block diagram in the current command control in the compressor. In the compressor 1, high-efficiency driving is realized when the mover 3 is driven at the resonance frequency ωL as described above. Therefore, it is necessary to perform frequency control so that the frequency ωI of the alternating current applied to the winding 6 becomes the resonance frequency ωL.

FIG. 6 is a diagram showing the relationship between the alternating current frequency ωI and the mover stroke under a constant current condition. The mover when the frequency ωI of the alternating current applied to the winding 6 is changed under the constant current condition. The stroke change of 3 is shown. Here, the constant current condition indicates that the effective value of the alternating current applied to the winding 6 is a constant value without being time-dependent. The horizontal axis in FIG. 6 is the frequency ωI of the alternating current, and the vertical axis is the stroke amount of the mover 3. Under a constant current condition, the electromagnetic excitation force Felec, which is an external force acting on the mover 3, has a constant value when the thrust constant is constant with respect to the stroke of the mover 3. Actually, as shown in FIG. 3, although the thrust constant varies somewhat with respect to the stroke of the mover 3, it is assumed here that the thrust constant is constant.
Considering the case where the frequency ωI of the alternating current becomes the resonance frequency ωL, resonance due to the electromagnetic excitation force Felec occurs, so that the stroke amount of the mover 3 increases rapidly. In a reciprocating compressor such as the compressor 1, the stroke amount of the mover 3 is a parameter related to the discharge flow rate of the compression medium, and thus control is important. Further, if the stroke amount of the mover 3 becomes excessively large, the piston 12 may collide with the cylinder head 13. Therefore, it is necessary to control the stroke amount of the mover 3 according to the discharge flow rate of the compression medium required by the system or equipment connected to the compressor 1.
Here, a circuit equation in the compressor 1 is considered. The alternating voltage applied to the winding 6 is V, the current flowing through the winding 6 is I, the inductance of the winding 6 is L, the electrical resistance is R, the position of the mover 3 is x, the thrust constant is K, and the time is t. Then, the following formula (5) is established.

As shown in FIG. 5, the control block in current command control includes a stroke control unit 51, a position estimation unit 52, a frequency control unit 53, a current control unit 54, a voltage conversion unit 55, and an inverter 56.
The current value I flowing through the winding 6 detected by the current detection unit (not shown in FIGS. 1 and 5) is input to the position estimation unit 52, the frequency control unit 53, and the current control unit 54, respectively.

The position estimation unit 52 calculates the above equation (5) using the input current value I and the alternating voltage V applied to the winding 6, and outputs the estimated position x ^ of the mover 3 to the stroke control unit 51. To do.
The stroke control unit 51 obtains the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52 as the stroke command x ^**. The stroke command x ^** is output to the current control unit 54. Here, the stroke command x ^** is represented by x ^** = X ^** sin (ωI · t + φ). X ^** is a command stroke amplitude value of the mover 3. The stroke control unit 51 obtains the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52 as the stroke command x ^**. The control according to the discharge flow rate (load) of the compression medium required by the system or equipment connected to the compressor 1 is executed.

The current control unit 54 generates a current value corresponding to the stroke of the mover 3 as a current command value I ^* for the stroke command x ^** (required stroke amount) input from the stroke control unit 51. That is, the current control unit 54 calculates a current command value I ^* corresponding to the commanded stroke amount, and the current amount actually applied to the winding 6 via the inverter 56 is the calculated current command value I. Control to approach ^* . The current control unit 54 outputs the generated current command value I ^* to the voltage conversion unit 55.
When the voltage conversion unit 55 inputs the current command value I ^* from the current control unit 54, the voltage is finally applied to the motor terminal or the winding 6, so the current command value I ^* is output as the output voltage command value. Convert to v. The voltage conversion unit 55 outputs the converted output voltage command value v to the inverter 56.

On the other hand, in order to drive the compressor 1 with high efficiency, the frequency ωI of the alternating current needs to be matched with the resonance frequency ωL as described above. Since the resonance frequency ωL depends on the gas spring component Fr of the gas to be compressed as described above, the resonance frequency ωL can change depending on various conditions such as the stroke amount of the piston 12, the gas suction pressure to the cylinder 11a, and the gas discharge pressure. Therefore, in order to drive the compressor 1 with high efficiency, the frequency control unit 53 executes control to adjust the frequency ωI of the input current value I (alternating current) to the resonance frequency ωL according to the operating state each time. To do. That is, the frequency control unit 53 adjusts the frequency ωI of the current value I (alternating current) input so as to be the resonance frequency ωL, and outputs it to the current control unit 54.

From the above, when the compressor is driven, it is necessary to execute “stroke control” and “frequency control” in parallel, but if the frequency ωI of the alternating current is slightly changed as shown in FIG. Since the stroke amount of No. 3 changes greatly, there is a concern that control is difficult and the convergence of the control is poor.

[Voltage command control]
In the voltage command control, the voltage value of the alternating voltage applied to the winding 6 is controlled. FIG. 7 shows a control block diagram in the voltage command control in the compressor. A difference from the control block in the current command control shown in FIG. 5 described above is that a voltage control unit 57 is provided instead of the current control unit 54 and the voltage conversion unit 55.

FIG. 8 is a diagram showing the relationship between the alternating voltage frequency ωv and the mover stroke under a constant voltage condition. The mover when the frequency ωv of the alternating voltage applied to the winding 6 is changed under the constant voltage condition. The stroke change of 3 is shown. Here, the constant voltage condition indicates that the effective value of the alternating voltage applied to the winding 6 is a constant value without depending on time. The horizontal axis in FIG. 8 represents the frequency ωv of the alternating voltage, and the vertical axis represents the stroke amount of the mover 3.

Here, a circuit equation in the compressor 1 is considered. The alternating voltage applied to the winding 6 is V, the current flowing through the winding 6 is I, the inductance of the winding 6 is L, the electrical resistance is R, the position of the mover 3 is x, the thrust constant is K, and the time is t. Then, the above equation (5) is established.
In general, in a motor designed to have good motor efficiency, an induced voltage K (generated by the movement of the mover 3 rather than a voltage drop RI due to resistance or an induced electromotive force L (dI / dt) due to inductance. dx / dt) is dominant among the components of the alternating voltage V. Therefore, the speed (dx / dt) of the mover 3 can be regarded as substantially constant under the condition where the alternating voltage V is constant. This means that the voltage command control substantially approximates the speed control of the mover 3. Here, it is assumed that the position x of the mover 3 can be represented by a sine wave as in the following formula (6).

At this time, the speed (dx / dt) of the mover 3 is expressed by the following equation (7).

Therefore, unless the frequency ωv of the alternating voltage is largely changed, the control of the speed (dx / dt) of the mover 3 can be approximated to the control of the vibration amplitude (stroke amount) X0 of the mover 3. This means that the stroke amount of the mover 3 is substantially constant under the condition where the alternating voltage V is constant.

As is clear from the above circuit equations (5) to (7), the change in stroke of the mover 3 when the frequency ωv of the alternating voltage V applied to the winding 6 is changed under a constant voltage condition is shown in FIG. Compared with the constant current condition shown in FIG. It should be noted that whether the stroke amount of the mover 3 increases or decreases according to the frequency ωv of the alternating voltage V depends on operating conditions and motor parameters, and is not limited to this.
From the above, in the voltage command control, even if the frequency ωv of the alternating voltage is changed, unlike the current command control, the stroke amount of the mover 3 does not change greatly. Therefore, it becomes easy to execute “stroke control” and “frequency control” in parallel.

As shown in FIG. 7, the control block in the voltage command control includes a stroke control unit 51, a position estimation unit 52, a frequency control unit 53, a voltage control unit 57, and an inverter 56.
The current value I flowing through the winding 6 detected by the current detection unit (not shown in FIGS. 1 and 7) is input to the position estimation unit 52, the frequency control unit 53, and the voltage control unit 57, respectively.

The position estimation unit 52 calculates the above equation (5) using the input current value I and the alternating voltage V applied to the winding 6, and outputs the estimated position x ^ of the mover 3 to the stroke control unit 51. To do.
The stroke control unit 51 obtains the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52 as the stroke command x ^**. The stroke command x ^** is output to the current control unit 54. Here, the stroke command x ^** is expressed by x ^** = X ^** sin (ωv · t + φ). X ^** is a command stroke amplitude value of the mover 3. The stroke control unit 51 obtains the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52 as the stroke command x ^**. The control according to the discharge flow rate (load) of the compression medium required by the system or equipment connected to the compressor 1 is executed.

The voltage control unit 57 generates a voltage value corresponding to the stroke of the mover 3 as an output voltage command value v with respect to the stroke command x ^** (required stroke amount) input from the stroke control unit 51. That is, the voltage control unit 57 calculates the output voltage command value v corresponding to the commanded stroke amount, and the voltage actually applied to the winding 6 via the inverter 56 is the calculated output voltage command value v. Control to approach. Voltage control unit 57 outputs generated output voltage command value v to inverter 56.
The frequency control unit 53 uses the input current value I (alternating current) to adjust the frequency ωv of the alternating voltage V so as to be the resonance frequency ωL by the above equation (5), and outputs it to the voltage control unit 57. .

Next, the current waveform during voltage command control will be described. FIG. 9 is a diagram illustrating an example of a voltage waveform and a current waveform during voltage command control. The horizontal axis in FIG. 9 is time, and the vertical axis is voltage value / current value. Here, as a typical example, a waveform when a sinusoidal command is output as a voltage command waveform is shown. In the case of voltage command control, the actual voltage waveform (broken line in FIG. 9) becomes a sinusoidal waveform as commanded by voltage control. On the other hand, the current waveform is a waveform as shown by a solid line in FIG. 9 because the current waveform includes a higher-order frequency component of the drive frequency due to the nonlinear characteristic of the external force acting on the mover 3 described above. As described above, the current of the higher-order frequency component increases the amount of eddy current loss generated in the laminated electromagnetic steel sheet constituting the magnetic pole 4 of the motor unit, and can be a factor that deteriorates the motor efficiency. Can be.

(Configuration of control device 5)
FIG. 10 is a block diagram of the control device shown in FIG. As shown in FIG. 10, the control device 5 includes a stroke control unit 51, a position estimation unit 52, a frequency control unit 53, a voltage control unit 57, a fundamental wave extraction unit 58, a current control unit (harmonic attenuation unit) 59, and An inverter 56 is provided.
A current value I flowing through the winding 6 detected by a current detection unit (not shown in FIGS. 1 and 5) is input to the fundamental wave extraction unit 58. The fundamental wave extraction unit 58 separates the input current value I into a fundamental wave component (fundamental wave) and a high frequency component (harmonic wave). Then, the fundamental wave extraction unit 58 outputs the separated fundamental waves to the position estimation unit 52, the frequency control unit 53, and the voltage control unit 57, respectively. Further, the fundamental wave extraction unit 58 outputs the separated harmonics to the current control unit (harmonic attenuation unit) 59. Here, the fundamental wave is a drive frequency component of the compressor 1. As a fundamental wave extraction method, for example, a time-domain signal is converted into a frequency-domain signal by Fourier transform, and then a corresponding frequency-domain signal is extracted. In addition, although the present Example shows the structure which outputs the fundamental wave isolate | separated by the fundamental wave extraction part 58 to the position estimation part 52, it is not necessarily restricted to this. For example, the current value I flowing through the winding 6 detected by the current detection unit may be input to the fundamental wave extraction unit 58 and the position estimation unit 52. In other words, the position estimation unit 52 may be configured to input a signal including the fundamental wave component of the current value I and its higher order components.

The position estimation unit 52 calculates the above equation (5) using the fundamental wave input from the fundamental wave extraction unit 58 and the alternating voltage V applied to the winding 6 to obtain the estimated position x ^ of the mover 3. Output to the stroke controller 51. As described above, the equation (5) is a differential equation showing the relationship between the voltage value V of the alternating voltage, the current value I of the alternating current, and the position x of the mover 3, and the voltage value V and the current value I (here, the basic value) If the fundamental wave input from the wave extraction unit 58 is given, the position x of the mover 3 (the estimated position x ^ of the mover 3) can be obtained. As the voltage value V, a detected value of the alternating voltage V applied to the winding 6 may be used, and an output voltage command value v described later may be used as the voltage value V.

The stroke control unit 51 obtains the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52 as the stroke command x ^**. The stroke command x ^** is output to the voltage control unit 57. That is, the stroke control unit 51 performs control to bring the stroke of the mover 3 close to the stroke amount determined according to the discharge flow rate (load) of the compression medium required by the system or equipment connected to the compressor 1. Execute. In this embodiment, the stroke control unit 51 calculates the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52. Although a configuration in which x ^** is output to the voltage control unit 57 is shown, the configuration is not necessarily limited thereto. For example, the stroke control unit 51 converts the stroke of the mover 3 into the stroke command x ^* based on the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52. The stroke command x ^** may be obtained by PI control so as to approach. Further, using other feedback control such as PID control, the stroke of the mover 3 is determined based on the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52. A configuration may be ^{employed in} which the stroke command x ^** is determined so as to be close to the stroke command x ^* .

The frequency control unit 53 determines the frequency ωv ^{* of the} voltage waveform to be generated based on the fundamental wave input from the fundamental wave extraction unit 58. That is, the frequency control unit 53 performs control so that the frequency ωv of the alternating voltage approaches the resonance frequency ωL, and outputs the frequency ωv ^{* of the} voltage waveform to the voltage control unit 57. The frequency control unit 53 uses, for example, the phase relationship between the alternating current I flowing through the winding 6 (here, the fundamental wave input from the fundamental wave extracting unit 58), the alternating voltage V, and the position x of the mover 3. If the influence of the frictional damping force acting on the mover 3 and the inductance component of the motor is ignored during no load during resonance operation, the alternating current I and the alternating voltage V have the same phase, and the position x of the mover 3 Is in a relationship that the phase is delayed by 90 ° with respect to the current I. Based on such a relationship, it is possible to control the drive frequency by estimating the phase relationship during loading and controlling the phase of the output voltage V. For example, in the present embodiment, it is assumed that the frequency controller 53 simply assumes a configuration in which the phase difference between the fundamental wave component (fundamental wave) of the current value I and the phase difference between the output voltage V is close to zero. A configuration may be adopted in which the calculation is performed in consideration of the influence of the frictional damping force acting on the child 3 and the inductance component of the motor. Further, the phase of the output voltage V may be controlled using the relationship between the phase of the position estimated value x ^ of the mover 3 and the phase difference between the output voltage V. Note that control for bringing the phase difference between the phase of the fundamental wave component (fundamental wave) of the current value I and the output voltage V close to zero may use other feedback control such as PI control or PID control. As described above, controlling the phase of the output voltage V is substantially equivalent to controlling the frequency ωv of the output voltage V. For example, in order to advance the phase of the output voltage V, it can be achieved by performing positive feedback (increasing the frequency) with respect to the frequency ωv of the output voltage V, and in order to delay the phase of the output voltage V, This can be achieved by performing negative feedback (decreasing the frequency) with respect to the frequency ωv of the output voltage V.

The voltage control unit 57 outputs the output voltage amplitude (command voltage amplitude V ^*) based on the command frequency ωv ^* of the output voltage V input from the frequency control unit 53 and the stroke command value x ^** input from the stroke control unit 51 ^. ). Specifically, the circuit equation in the compressor 1 shown in the above equation (5) is used. In the present embodiment, as described above, since the induced voltage K (dx / dt) generated by the movement of the mover 3 is dominant among the components of the alternating voltage V, the command voltage amplitude V ^{* is set} to the command stroke amplitude. Using value X ^** , it determines like following Formula (8).

However, for the purpose of further increasing accuracy, the command voltage amplitude V ^* (output voltage) is calculated by using the current value I (fundamental wave input from the fundamental wave extraction unit 58) using the above equation (5). (Amplitude) may be determined.

The current control unit (harmonic attenuation unit) 59 inputs the high frequency component (harmonic) separated by the fundamental wave extraction unit 58 and determines a voltage correction amount for bringing the high frequency component (harmonic) close to zero. And output as a harmonic attenuation voltage. Specifically, the voltage correction amount is calculated from the high frequency component of the current value I separated by the fundamental wave extraction unit 58 based on the circuit equation in the compressor 1 shown in the above equation (5).
The command voltage amplitude V ^* (output voltage amplitude) output from the voltage control unit 57 and the harmonic attenuation voltage output from the current control unit (harmonic attenuation unit) 59 are added, and the inverter 56 is used as the output voltage command value v. And an alternating voltage is applied to the winding 6 by the inverter 56.

According to the output voltage command value v generated by the control device 5 of the present embodiment, it is easy to execute “stroke control” and “frequency control” in parallel, and further, a current control unit (harmonic attenuation unit). ) 59, voltage correction for attenuating the higher-order frequency component of the drive frequency in the current waveform is executed, so that the alternating current flowing in the winding 6 is prevented from including the higher-order frequency component of the drive frequency. Can do.

FIG. 11 is a diagram showing a modification of the block diagram of the control device shown in FIG. The control device 5 shown in FIG. 11 is different from the control device shown in FIG. 10 in that the estimated position x ^ of the mover 3 is input from the position estimation unit 52 to the frequency control unit 53. The frequency control unit 53 configuring the control device 5 illustrated in FIG. 11 includes the fundamental wave of the current value I separated by the fundamental wave extraction unit 58, the alternating voltage V, and the position of the mover 3 input from the position estimation unit 52. Based on at least two of the estimated values x ^, the frequency ωv ^{* of the} voltage waveform to be generated is determined by the above equation (5).

As described above, according to this embodiment, it is possible to provide a linear motor control system that can improve drive efficiency and vibration noise characteristics.

FIG. 12 is a block diagram of the control device according to the second embodiment according to another embodiment of the present invention. In the present embodiment, the position estimation unit 52a has a command voltage amplitude V ^* (output voltage amplitude) output from the voltage control unit 57a and a harmonic attenuation voltage output from the current control unit (harmonic attenuation unit) 59. The difference from the first embodiment shown in FIG. 10 described above is that the added output voltage command value v is input to obtain the estimated position value x ^ of the mover 3. The configuration of the compressor 1 shown in FIG. 1 is the same as that of the first embodiment. Below, the same code | symbol is attached | subjected to the component similar to Example 1, and the overlapping description is abbreviate | omitted.

As shown in FIG. 12, the position estimation unit 52a configuring the control device 5a of the present embodiment includes the fundamental wave input from the fundamental wave extraction unit 58 and the command voltage amplitude V ^* (output from the voltage control unit 57a. The output voltage command value v obtained by adding the output voltage amplitude) and the harmonic attenuation voltage output from the current control unit (harmonic attenuation unit) 59 is input, and the above-described equation (5) is calculated to obtain the mover. 3 is obtained, and the obtained estimated position x ^ of the mover 3 is output to the stroke controller 51a.

The stroke control unit 51a obtains the difference (deviation) between the stroke command x ^* set according to the load and the estimated position x ^ of the mover 3 input from the position estimation unit 52 as the stroke command x ^**. The stroke command x ^** is output to the voltage controller 57a. That is, the stroke control unit 51a performs control to bring the stroke of the mover 3 close to the stroke amount determined according to the discharge flow rate (load) of the compression medium required by the system or equipment connected to the compressor 1. Execute.

The voltage control unit 57a, command frequency ωv of the output voltage V inputted from the frequency control unit 53 ^*, and on the basis of the stroke command value x ^** inputted from the stroke control unit 51a, the output voltage amplitude (the command voltage amplitude V ^* ). Specifically, the circuit equation in the compressor 1 shown in the above equation (5) is used. In the present embodiment, as described above, since the induced voltage K (dx / dt) generated by the movement of the mover 3 is dominant among the components of the alternating voltage V, the command voltage amplitude V ^{* is set} to the command stroke amplitude. The above equation (8) is calculated using the value X ^** to determine the command voltage amplitude V ^* (output voltage amplitude).

Thus, in addition to the fundamental wave input from the fundamental wave extraction unit 58, the position estimation unit 52a of the present embodiment includes the command voltage amplitude V ^* (output voltage amplitude) output from the voltage control unit 57a and the current control unit. (Harmonic attenuation unit) Since the estimated position x ^ of the mover 3 is obtained based on the output voltage command value v obtained by adding the harmonic attenuation voltage output from the 59, the above-described first embodiment is used. In comparison, the position estimation accuracy of the mover 3 is improved.

According to the output voltage command value v generated by the control device 5a of the present embodiment, it is easy to execute “stroke control” and “frequency control” in parallel, and further, a current control unit (harmonic attenuation unit). ) 59, voltage correction for attenuating the higher-order frequency component of the drive frequency in the current waveform is executed, so that the alternating current flowing in the winding 6 is prevented from including the higher-order frequency component of the drive frequency. Can do.

FIG. 13 is a diagram showing a modification of the block diagram of the control device shown in FIG. The control device 5a shown in FIG. 12 is different from the control device shown in FIG. 12 in that the estimated position x ^ of the mover 3 is input to the frequency control unit 53 from the position estimation unit 52a. The frequency control unit 53 constituting the control device 5a shown in FIG. 13 includes the fundamental wave of the current value I separated by the fundamental wave extraction unit 58, the alternating voltage V, and the position of the mover 3 input from the position estimation unit 52. Based on at least two of the estimated values x ^, the frequency ωv ^{* of the} voltage waveform to be generated is determined by the above equation (5).

As described above, according to the present embodiment, in addition to the effects of the first embodiment, it is possible to improve the position estimation accuracy of the mover.

FIG. 14 is a block diagram of the control device according to the third embodiment according to another embodiment of the present invention. In the present embodiment, the current control unit (harmonic attenuation unit) 59b calculates the high frequency component (harmonic) separated by the fundamental wave extraction unit 58 and the estimated position x ^ of the mover 3 obtained by the position estimation unit 52. This is different from the first embodiment shown in FIG. 10 described above in that it is configured to input and determine the harmonic attenuation voltage as a voltage correction amount. The configuration of the compressor 1 shown in FIG. 1 is the same as that of the first embodiment. Below, the same code | symbol is attached | subjected to the component similar to Example 1, and the overlapping description is abbreviate | omitted.

As shown in FIG. 14, the current control unit (harmonic attenuation unit) 59 b that constitutes the control device 5 b of this embodiment includes the high-frequency component (harmonic) and the position of the current value I separated by the fundamental wave extraction unit 58. The estimated position x ^ of the mover 3 obtained by the estimation unit 52 is input. Based on the high frequency component (harmonic) of the current value I and the estimated position x ^ of the mover 3, the current control unit (harmonic attenuation unit) 59b sets a voltage correction amount for bringing the high frequency component of the current value I close to zero. Determined and output as harmonic attenuation voltage.
In the first embodiment described above, the current control unit (harmonic attenuation unit) 59 determines the voltage correction amount in consideration of only items related to the current value I in the circuit equation of the compressor 1 of Formula (5). It is configured. On the other hand, in the present embodiment, in the circuit equation of Expression (5), the current control unit (harmonic attenuation unit) is also considered in consideration of the induced voltage K (dx / dt) involving the position (velocity) of the mover 3. ) 59b determines the voltage correction amount. Therefore, the voltage correction amount for making the high frequency component of the current value I approach zero can be determined with higher accuracy than in the first embodiment.

According to the output voltage V generated by the control device 5b of the present embodiment, it is easy to execute “stroke control” and “frequency control” in parallel, and further, the current waveform has a higher-order frequency component of the drive frequency. Therefore, it is possible to suppress the alternating current flowing through the winding 6 from including a higher-order frequency component of the drive frequency.

As described above, according to the present embodiment, in addition to the effects of the first embodiment, it is possible to determine the voltage correction amount for bringing the high frequency component of the current value I closer to zero with higher accuracy than the first embodiment. It becomes possible.

FIG. 15 is a block diagram of the control device according to the fourth embodiment according to another embodiment of the present invention. In the present embodiment, the position estimation unit 52a has a command voltage amplitude V ^* (output voltage amplitude) output from the voltage control unit 57a and a harmonic attenuation voltage output from the current control unit (harmonic attenuation unit) 59. The fundamental voltage extraction unit 58 separates the point where the added output voltage command value v is input and the position estimation value x ^ of the mover 3 is obtained and the current control unit (harmonic attenuation unit) 59c. The high frequency component (harmonic) and the estimated position x ^ of the mover 3 obtained by the position estimation unit 52 are input, and the harmonic attenuation voltage as the voltage correction amount is determined. Different from Example 1 shown in FIG. The configuration of the compressor 1 shown in FIG. 1 is the same as that of the first embodiment. Below, the same code | symbol is attached | subjected to the component similar to Example 1, and the overlapping description is abbreviate | omitted.

As shown in FIG. 15, the position estimation unit 52a constituting the control device 5c of the present embodiment includes the fundamental wave input from the fundamental wave extraction unit 58 and the command voltage amplitude V ^* (output from the voltage control unit 57a. The output voltage command value v obtained by adding the output voltage amplitude) and the harmonic attenuation voltage output from the current control unit (harmonic attenuation unit) 59 is input, and the above-described equation (5) is calculated to obtain the mover. 3 is obtained, and the obtained estimated position x ^ of the mover 3 is output to the stroke controller 51a.

The voltage control unit 57a outputs the output voltage amplitude (command voltage amplitude V ^* based on the command frequency ωv ^* of the output voltage V input from the frequency control unit 53 and the stroke command value x ^** input from the stroke control unit 51a ^. ). Specifically, the circuit equation in the compressor 1 shown in the above equation (5) is used. In the present embodiment, as described above, since the induced voltage K (dx / dt) generated by the movement of the mover 3 is dominant among the components of the alternating voltage V, the command voltage amplitude V ^{* is set} to the command stroke amplitude. The above equation (8) is calculated using the value X ^** to determine the command voltage amplitude V ^* (output voltage amplitude).

The current control unit (harmonic attenuation unit) 59c inputs the high frequency component (harmonic) of the current value I separated by the fundamental wave extraction unit 58 and the estimated position x ^ of the mover 3 obtained by the position estimation unit 52a. To do. Based on the high frequency component (harmonic) of the current value I and the estimated position x ^ of the mover 3, the current control unit (harmonic attenuation unit) 59b sets a voltage correction amount for bringing the high frequency component of the current value I close to zero. Determined and output as harmonic attenuation voltage.

Further, the current control unit (harmonic attenuation unit) 59c of the present embodiment has high accuracy obtained by the position estimation unit 52a in addition to the high frequency component (harmonic) of the current value I separated by the fundamental wave extraction unit 58. Since the voltage correction amount for determining the high frequency component of the current value I to be close to zero is determined based on the estimated position x ^ of the mover 3, the high frequency component of the current value I is brought closer to zero with higher accuracy. Therefore, the voltage correction amount can be determined.

According to the output voltage V generated by the control device 5c of the present embodiment, it is easy to execute “stroke control” and “frequency control” in parallel, and further, the current waveform has a higher-order frequency component of the drive frequency. Therefore, it is possible to suppress the alternating current flowing through the winding 6 from including a higher-order frequency component of the drive frequency.

As described above, according to the present embodiment, in addition to the effects of the first embodiment, it is possible to improve the position estimation accuracy of the mover, and the current value I in consideration of the estimated position of the mover with high accuracy. Therefore, the voltage correction amount for bringing the high frequency component of the current value I closer to zero can be determined with higher accuracy.

The compressor 1 (linear compressor) shown as an example of the linear motor control system in the first to fourth embodiments described above is an air conditioner including a heat exchanger that functions as a condenser or an evaporator. It can be applied to a compressor for pressure feeding.
The compressor 1 (linear compressor) shown as an example of the linear motor control system in the first to fourth embodiments is applied to a compressor that compresses a working fluid in order to adjust the vehicle height in the air suspension. it can.
Furthermore, the compressor 1 (linear compressor) shown as an example of the linear motor control system in the first to fourth embodiments described above is a compressor that pumps liquid refrigerant in a refrigerator having a condenser and an evaporator. Is also applicable.
Furthermore, the compressor 1 (linear compressor) shown as an example of the linear motor control system in the first to fourth embodiments can be applied to a refrigeration air conditioner such as a cryostat or an air conditioner.

In addition, this invention is not limited to an above-described Example, Various modifications are included.
For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Armature, 3 ... Movable element (field element), 3a ... Permanent magnet, 4 ... Magnetic pole, 5, 5a, 5b, 5c ... Control Device: 6 ... Winding, 7 ...

Bridge

7, 11 ... Cylinder block, 11a ... Cylinder, 12 ... Piston, 13 ... Cylinder head, 14 ... Resonant spring, 51 , 51a... Stroke controller, 52, 52a ... position estimator, 53 ... frequency controller, 54 ... current controller, 55 ... voltage converter, 56 ... inverter, 57 , 57a ... voltage control unit, 58 ... fundamental wave extraction unit, 59, 59b, 59c ... current control unit (harmonic attenuation unit)

Claims

A device having one end connected to an elastic body and having a permanent magnet, and an armature having a winding wound around a magnetic pole, and reciprocating the field element and the armature relatively in the axial direction; ,
A controller for controlling an alternating voltage applied to the winding based on an alternating current flowing through the winding detected by a current detection unit, and a linear motor control system comprising:
The control device includes:
A fundamental wave extraction unit that separates an alternating current flowing through the winding detected by the current detection unit into a fundamental wave component and a harmonic component;
A harmonic attenuation unit that outputs a harmonic attenuation voltage capable of attenuating the harmonic component, and
A linear motor control system that controls an alternating voltage applied to the winding based on a fundamental wave component and a harmonic attenuation voltage of an alternating current.
The linear motor control system according to claim 1,
The control device includes:
A linear motor control system comprising a frequency control unit that controls the frequency of the fundamental wave component of the alternating current to approach the resonance frequency and outputs the frequency of the alternating voltage.
The linear motor control system according to claim 2,
The linear motor control system according to claim 1, wherein the resonance frequency is a frequency determined based on an external force acting between the field element and the armature and a mass of the field element.
In the linear motor control system according to claim 3,
The control device includes:
A position estimation unit that estimates the position of the field element based on at least a fundamental wave component of the alternating current or an alternating current flowing through the winding detected by the current detection unit;
A stroke control unit that outputs, as a second stroke command, a difference between the first stroke command of the field element set according to the load and the estimated position of the field element estimated by the position estimation unit;
A linear motor control system that controls an alternating voltage applied to the winding based on the second stroke command and the frequency of the alternating voltage output from the frequency control unit.
In the linear motor control system according to claim 4,
The control device includes:
A voltage control unit for determining an output voltage amplitude based on the second stroke command output from the stroke control unit and the frequency of the alternating voltage output from the frequency control unit;
A linear motor control system that controls an alternating voltage applied to the winding based on the determined output voltage amplitude.
In the linear motor control system according to claim 5,
The control device includes:
An inverter for applying an alternating voltage to the winding;
An output voltage command value generated by adding the output voltage amplitude determined by the voltage control unit and the harmonic attenuation voltage output from the harmonic attenuation unit is output to the inverter. Linear motor control system.
The linear motor control system according to claim 6,
The frequency control unit outputs a frequency of an alternating voltage based on a fundamental wave component of the alternating current and an estimated position of a field element estimated by the position estimating unit.
The linear motor control system according to claim 6,
The position estimation unit includes an output voltage command value generated by adding the output voltage amplitude determined by the voltage control unit and the harmonic attenuation voltage output from the harmonic attenuation unit, and the alternating current. A linear motor control system that estimates a position of the field element based on a fundamental wave component or an alternating current flowing through the winding detected by the current detection unit.
The linear motor control system according to claim 8, wherein
The frequency control unit outputs a frequency of an alternating voltage based on a fundamental wave component of the alternating current and an estimated position of a field element estimated by the position estimating unit.
The linear motor control system according to claim 6,
The harmonic attenuation unit is a harmonic attenuation voltage capable of attenuating the harmonic component based on the harmonic component separated by the fundamental wave extraction unit and the estimated position of the field element estimated by the position estimation unit. A linear motor control system characterized by
The linear motor control system according to claim 10,
The position estimation unit includes an output voltage command value generated by adding the output voltage amplitude determined by the voltage control unit and the harmonic attenuation voltage output from the harmonic attenuation unit, and the alternating current. A linear motor control system that estimates a position of the field element based on a fundamental wave component or an alternating current flowing through the winding detected by the current detection unit.
The linear motor control system according to claim 6,
The linear motor control system, wherein the field element is a mover and reciprocates in an axial direction with respect to the armature.
In the linear motor control system according to claim 7,
The linear motor control system, wherein the field element is a mover and reciprocates in an axial direction with respect to the armature.
The linear motor control system according to claim 8, wherein
The linear motor control system, wherein the field element is a mover and reciprocates in an axial direction with respect to the armature.
In the linear motor control system according to claim 9,
The linear motor control system, wherein the field element is a mover and reciprocates in an axial direction with respect to the armature.
The linear motor control system according to claim 10,
The linear motor control system, wherein the field element is a mover and reciprocates in an axial direction with respect to the armature.
The linear motor control system according to claim 11,
The linear motor control system, wherein the field element is a mover and reciprocates in an axial direction with respect to the armature.